Population distribution People are not evenly distributed over the earth's surface. This is due to both physical and human factors. Physical factors such as relief, soils and climate can encourage high densities of population. Densely populated areas are likely where there are areas of low, flat land with fertile soils and a temperate climate. However, where the climate is very hot, or very cold, where there are high mountains or deserts, the environment is hostile to people and these areas are often only sparsely populated.
The map above shows the distribution of the world's population. The red dots represent 100,000 people. For the exam you need to be able to describe the distribution or spread of people over the world. In simple terms this means say where the red areas are on the planet.
Distibution = the spread of people over an area
Density = the number of people living in a set area usually 1sqkm
Reasons for different population distributions and densities
Population density – physical factors leading to high density ·Relief - Lowland areas which are flat are easier to farm and build settlements and transport links ·Climates - Moderate climates with enough rain and warm temperatures to allow crops to grow and ripen e.g. W. Europe & Japan. ·Soil - Thick fertile such as loams and alluvium promote agricultural production such as S.E. England. ·Vegetation - Areas of open woodland and grassland are easy to settle in. e.g. The Pampas in Argentina. ·Accessibility - Coastal areas with easy access to transport and trade ·Resources - Plenty of water, timber, minerals such as coal, oil and copper enable countries to develop. e.g. Western Europe & Eastern America Population density – physical factors leading to low density ·Relief - Mountainous areas are too steep to farm easily and are difficult to build on and get around easily. ·Climates - Very cold, very hot and too dry affect the growing season and make cultivation impossible - also unpleasant to live in such areas. e.g. The Arctic, Sahara Desert, etc. ·Soil - Thin, rocky and acidic soils all result in low agricultural production such as hot deserts and mountainous areas. ·Vegetation - Very dense jungle and swamps make it difficult to penetrate and use productively. e.g. Amazon Rainforest. ·Accessibility - Interior areas of large continents such as Africa and Asia struggle to develop ·Resources - Few economic resources make it difficult for a country to trade with other countries. Population density – human factors leading to high density ·Economic - Large rich markets for trade, good infrastructure such as roads, railways etc as well as a skilled and varied labour force ·Social - Some groups of people prefer to live together for security and friendship such as Europeans, Japanese etc ·Political - Stable and fair government - usually democracies such as W. Europe, Singapore etc Population density – human factors leading to low density ·Economic - Poor trading links and markets, poor infrastructure with few roads and services such as Central Africa, Amazon Basin and limited job opportunities for the inhabitants ·Social - Some groups of people prefer to be more isolated such as Scandinavians ·Political - Unstable governments and civil wars - in such areas as Afghanistan, Zimbabwe and the Sudan
Exponential Growth
The world's population has grown exponentially. This means that the rate of growtgh has become increasingly rapid. The growth in the last 1000 years has been dramatic.In the year 2000 there were 10 times as many people living than there had been before in 1700. Not only is the population increasing but the rate of increase is becoming greater.
Population grew especially quickly during the lath 20th and early 21st centuries. Between 2006 and 2007, 211, 090 people were added to world population every day. Growth is predicted to continue, but now the rate is slowing down. Population is likely to rise to 9.2 billion by 2050 and peaking at 10 billion in 2150. This should then be followed by a more stable period of zero growth or even natural decrease.
The graph above shows global population growth over time
Birth rate, death rate and natural change
Birth rate: the number of babies born per 1,000 people per year. Can be at high as 50 per 1000 per year but the availability of birth control means that such high birth rates are now rare.
Death rate: the nuber of deaths per 1,000 people. Normally death rates lie between 5 per 1,000 per year and 20 per 1,000 per year. This can increase significantly if there is an epidemic, famine or war.
Two factgors affect the level of the death rate:
health care has improved in poorer countries, lowering death rate
having so many people under the age of 15 reduces the chance of death
Natural change: this is the difference betwen birth and death rates in a country. It is a useful measure of a population's growth or decline.
Natural increase: this is when the birth rate exceeds the death rate. This has been the case recently except in periods of famine, war or epidemic. Some countries have reduced their birth rates and this has led to a natural decrease where the death rate exceeds the birth rate.
Life expectancy: the number of years a person is expected to live, usually taken from birth.
Population distribution
People are not evenly distributed over the earth's surface. This is due to both physical and human factors. Physical factors such as relief, soils and climate can encourage high densities of population. Densely populated areas are likely where there are areas of low, flat land with fertile soils and a temperate climate. However, where the climate is very hot, or very cold, where there are high mountains or deserts, the environment is hostile to people and these areas are often only sparsely populated.
The map above shows the distribution of the world's population. The red dots represent 100,000 people. For the exam you need to be able to describe the distribution or spread of people over the world. In simple terms this means say where the red areas are on the planet.
Distibution = the spread of people over an area
Density = the number of people living in a set area usually 1sqkm
Reasons for different population distributions and densities
Population density – physical factors leading to high density
· Relief - Lowland areas which are flat are easier to farm and build settlements and transport links
· Climates - Moderate climates with enough rain and warm temperatures to allow crops to grow and ripen e.g. W. Europe & Japan.
· Soil - Thick fertile such as loams and alluvium promote agricultural production such as S.E. England.
· Vegetation - Areas of open woodland and grassland are easy to settle in. e.g. The Pampas in Argentina.
· Accessibility - Coastal areas with easy access to transport and trade
· Resources - Plenty of water, timber, minerals such as coal, oil and copper enable countries to develop. e.g. Western Europe & Eastern America
Population density – physical factors leading to low density
· Relief - Mountainous areas are too steep to farm easily and are difficult to build on and get around easily.
· Climates - Very cold, very hot and too dry affect the growing season and make cultivation impossible - also unpleasant to live in such areas. e.g. The Arctic, Sahara Desert, etc.
· Soil - Thin, rocky and acidic soils all result in low agricultural production such as hot deserts and mountainous areas.
· Vegetation - Very dense jungle and swamps make it difficult to penetrate and use productively. e.g. Amazon Rainforest.
· Accessibility - Interior areas of large continents such as Africa and Asia struggle to develop
· Resources - Few economic resources make it difficult for a country to trade with other countries.
Population density – human factors leading to high density
· Economic - Large rich markets for trade, good infrastructure such as roads, railways etc as well as a skilled and varied labour force
· Social - Some groups of people prefer to live together for security and friendship such as Europeans, Japanese etc
· Political - Stable and fair government - usually democracies such as W. Europe, Singapore etc
Population density – human factors leading to low density
· Economic - Poor trading links and markets, poor infrastructure with few roads and services such as Central Africa, Amazon Basin and limited job opportunities for the inhabitants
· Social - Some groups of people prefer to be more isolated such as Scandinavians
· Political - Unstable governments and civil wars - in such areas as Afghanistan, Zimbabwe and the Sudan
Exponential Growth
The world's population has grown exponentially. This means that the rate of growtgh has become increasingly rapid. The growth in the last 1000 years has been dramatic.In the year 2000 there were 10 times as many people living than there had been before in 1700. Not only is the population increasing but the rate of increase is becoming greater.
Population grew especially quickly during the lath 20th and early 21st centuries. Between 2006 and 2007, 211, 090 people were added to world population every day. Growth is predicted to continue, but now the rate is slowing down. Population is likely to rise to 9.2 billion by 2050 and peaking at 10 billion in 2150. This should then be followed by a more stable period of zero growth or even natural decrease.
The graph above shows global population growth over time
Birth rate, death rate and natural change
Birth rate: the number of babies born per 1,000 people per year. Can be at high as 50 per 1000 per year but the availability of birth control means that such high birth rates are now rare.
Death rate: the nuber of deaths per 1,000 people. Normally death rates lie between 5 per 1,000 per year and 20 per 1,000 per year. This can increase significantly if there is an epidemic, famine or war.
Two factgors affect the level of the death rate:
- health care has improved in poorer countries, lowering death rate
- having so many people under the age of 15 reduces the chance of death
Natural change: this is the difference betwen birth and death rates in a country. It is a useful measure of a population's growth or decline.Natural increase: this is when the birth rate exceeds the death rate. This has been the case recently except in periods of famine, war or epidemic. Some countries have reduced their birth rates and this has led to a natural decrease where the death rate exceeds the birth rate.
Life expectancy: the number of years a person is expected to live, usually taken from birth.